Conventionally, gas barrier films prepared by forming an inorganic deposition film on the surface of a plastic base are used for applications requiring to block various gases such as a water vapor, an oxygen gas and the like. The gas barrier films are used for packaging various articles such as particularly, foods, drugs and medicines and industrial goods. In the gas barrier film, an inorganic deposition film is formed by vapor-depositing inorganic substances (including inorganic oxides) such as aluminum oxide, silicon oxide, magnesium oxide and the like by utilizing a physical vapor deposition (PVD) method such as a vacuum deposition method, a sputtering method or an ion plating method, a chemical vapor deposition (CVD) method such as a plasma chemical vapor deposition method, a thermal chemical vapor deposition method or a photochemical vapor deposition method, or the like.
In order to improve a gas barrier property of deposition films for packaging, various methods for treating the surface of the deposition film after forming a deposition film are employed. There is, for example, a method in which a metal oxide layer is formed on a film base by a PVD method or a CVD method and an inorganic-organic hybrid polymer layer is laminated on the metal oxide layer. Also, a method of vapor-depositing a mixture of aluminum oxide and silicon oxide on a film base, which is described in Patent Document 1, a method, described in Patent Document 2, in which an organosilicon gas is flown into a chamber between the surface of a film and a source of inorganic substances to be evaporated during the source of inorganic substances to be evaporated generates inorganic evaporated species, a method in which an inorganic oxide is vapor-deposited on a base and then the deposited base is coated with an organic substance and an inorganic oxide is further vapor-deposited thereon, and a method of vapor-depositing silicon oxide on a base are known.
However, in the case where a hybrid polymer was formed on the surface of an inorganic deposition film or a mixture of aluminum oxide and silicon oxide was vapor-deposited on a film base, even if an organosilicon gas was flown into a chamber between the surface of a film and a source of inorganic substances to be evaporated during the source of inorganic substances to be evaporated generates inorganic evaporated species, it was difficult to produce a gas barrier film having a high gas barrier property stably. Also, even if an inorganic oxide is vapor-deposited on a base and then the deposited base is coated with an organic substance and an inorganic oxide is further vapor-deposited thereon or silicon oxide is vapor-deposited on a base, there is a problem that these methods were expensive.
Patent Document 1: Japanese Unexamined Patent Publication No. 10-95067
Patent Document 2: Japanese Unexamined Patent Publication No. 4-251736